Fraudulent transactions are an ongoing problem. One way fraud is committed is by one individual stealing another individual's credit card and using that stolen card to perform transactions at physical locations, such as to purchase gasoline or groceries. Fraud can also be perpetrated in the context of electronic transactions. Electronic fraud can be particularly devastating because the perpetrator does not need physical access to a victim's credit card (or other resource) to perform the fraud. Improved techniques to prevent fraud would be useful. Improved techniques to identify those who commit fraud would also be useful.